Produção de amilase por rizóbios, usando farinha de pupunha como substrato

Abstract

ResumoAs amilases estão entre as mais importantes enzimas industriais e são de grande interesse na biotecnologia atual. Embora elas possam ser derivadas de diversas fontes, as de origem microbiana são geralmente as mais procuradas pelas indústrias. As espécies do gênero Bacillus são consideradas as principais fontes de amilases. Apesar disso, a busca por novas fontes microbianas vem crescendo em todo o mundo. O presente estudo objetivou avaliar a produção de amilase por rizóbios nativos, usando farinha de pupunha como substrato. Neste estudo, foi adotado o delineamento experimental inteiramente casualizado, com três repetições. Foram determinados ainda os coeficientes de correlação de Pearson entre as variáveis pH do meio, proteína extracelular, biomassa celular, diâmetro médio da colônia (DMC), diâmetro médio do halo (DMH), índice enzimático (IE) e atividade amilolítica das bactérias selecionadas. Dos 19 isolados com atividade amilolítica em meio YMA modificado, sete (36,8%) exibiram "IE" ≥ 2,1, o que permite considerá-los bons produtores de amilase. Os "IE" apresentados pelos isolados INPA R-987, 950 e 915B foram significativamente inferiores (p < 0,01) aos mostrados pelas bactérias INPA R-926, 975 e 957. A atividade amilolítica variou significativamente (p < 0,01) entre as bactérias investigadas. Os isolados INPA R-975 e R-926 apresentaram, respectivamente, a maior (1,00 U.min -1 .mL -1 ) e a menor (0,31 U.min -1 .mL -1 ) média de atividade. Em termos gerais, a proteína extracelular correlacionou-se positivamente com "IE" (r = 0,52*; p < 0,05) e "DMH" (r = 0,55*; p < 0,05). A biomassa celular apresentou correlações positivas com atividade amilolítica (r = 0,55*; p < 0,05) e "DMH" (r = 0,54*; p < 0,05) e negativa com o pH final do meio de cultivo (r = 0,93**; p < 0,01). Palavras-chave: atividade amilolítica; rizóbios; farinha de pupunha; Amazônia Central. AbstractAmylases are among the most important industrial enzymes and are of great significance in present-day biotechnology. Although they can be derived from various sources, enzymes from microbial sources are generally the most required by industry. Species of the genus Bacillus are considered to be the main sources of amylases, although screening for new microbial sources is increasing all over the world. The objective of the present study was to evaluate the production of amylase by indigenous rhizobia, using peach palm flour as substrate. In this study, a completely randomized experimental design was adopted with three replicates. Pearson's correlation coefficients were calculated for medium pH, extracellular protein, cellular biomass, mean colony diameter (MCD), mean halo diameter (MHD), enzymatic index (EI) and amylolytic activity variables from the bacteria selected. Out of the 19 rhizobia strains with amylolytic activity on modified YMA, seven (36.8%) strains showed "EI" ≥ 2,1, and they were considered as good producers of amylase. The "IE" presented by bacteria INPA R-987, R-950 and R-915B were significantly lower (p < 0.01) than those shown by the ...

Phenotypic diversity and amylolytic activity of fast growing rhizobia from pigeonpea &#91;Cajanus cajan (L.) Millsp.&#93;

“…The metabolic characterization of Brazilian rhizobial strains has shown a great versatility of their potential to other biotechnological applications than inoculant production, such as production of microbial biopolymers (2,8,9), and enzymes with industrial application (19,20,21).…”

“…The constant bioprospection of microorganisms able to produce amylase may result in microbial strains, which show higher amylase production than those, industrially available nowadays. Besides contributing to the selection of microorganisms to industrial production of amylase, the characterization of rhizobia regarding the amylolytic activity also must contribute to the understanding of the very diverse metabolic profiles of the root nodule bacteria (20,21,25). The aim of this study was to characterize rhizobial isolates from pigeonpea root nodules, by means of its phenotypic characteristics and evaluate the amylolytic capacity of the bacteria.…”

Characterization of α-Amylase Produced by the Endophytic Strain of Penicillium digitatum in Solid State Fermentation (SSF) and Submerged Fermentation (SmF)

“…Amylases are applied in the most varied industrial sectors that require the hydrolysis of starch, being mainly used in the food industry for the preparation of beers, jellies and to obtain free glucose for the most varied applications (Michelin, 2005). In addition to the food industry, these enzymes can be used in the formulation of detergents and in the paper, pharmaceutical, fermentation and textiles industries (Oliveira et al, 2007). There are two processes for the production of microbial enzymes: solid state fermentation (FES) and submerged fermentation (SmF).…”

Characterization of -amylase produced by the endophytic strain of Penicillium digitatum in solid state fermentation (SSF) and submerged fermentation (SMF)

“…In addition to the food industry, these enzymes can be used in the formulation of detergents and in the paper, pharmaceutical, fermentation and textiles industries (Oliveira et al, 2007). There are two processes for the production of microbial enzymes: solid state fermentation (FES) and submerged fermentation (SmF).…”